The Flocculation Properties of Magnesium Lignosulfonate in Red Liquid

Abstract

In alkaline conditions, magnesium salt of red liquor will produce precipitation phenomenon and generate colloidal substances. The sediment was mainly lignin sulfonate. In order to extract and separate the lignin sulfonate of red liquid, when the pH of red liquid adjusted to different pH with different alkaline solution, study on its relation to pH and the amount of alkali and precipitation, discuss the relationship to the content of precipitation lignin in red liquid, the viscosity of upper liquid after centrifugation and temperature as well. Adjusting the pH values of red liquid to 13 with NaOH, adjusting it to 12 with KOH, then adjusting its pH to 13 and adding 20 mL Ca(NO3)2. We got that the last kind of condition generate the biggest quantity of precipitation. The changes of temperature and the amount of calcium nitrate can also affect the formation of precipitation, under the optimal conditions of pH, each group of experiments got the largest amount of precipitation at 40 °C; The amount of precipitation increased following the increasing of calcium nitrate content; Ash content increased following the increasing of precipitation content.